Ukrainian officials said Monday that Russia had launched missiles on border regions where it has intensified attacks in recent days.

Overnight, Russia launched five missiles on the northeastern Kharkiv border region and also targeted the neighbouring Sumy border region with two missiles, the Ukrainian air force said.

Russia in recent weeks has stepped up air attacks on the northeastern Sumy region, which was partially occupied early in the war.

Russia has also pushed further in the east and in February captured the frontline eastern city of Avdiivka in the Donetsk region.

"The amount of shelling and the use of tactical aviation and multiple launch rocket systems has increased significantly compared to last week," the governor of Sumy region, Volodymyr Artiukh, said on television news Monday.

Overnight and on Monday morning, Russia shelled border areas and settlements 24 times, Sumy region's administration said on Telegram.

Artiukh said at the weekend that the Sumy region had been bombarded more than 3,000 times since the start of the year.

Sumy regional authorities said they have evacuated 285 residents, including 26 children, from border areas over the last week.

The regional authorities told residents not to panic, however, and to only trust official information, rather than Russian "psyops".

Russia also launched 22 drones on Ukraine overnight, 17 of which were shot down in various regions, the air force said.

The governor of the central Poltava region, Filip Pronin, said there were explosions in the Kremenchuk district -- where Russia has targeted an oil refinery -- but no casualties nor damage to infrastructure.